Format numbers

Cargo.lock

@@ -1143,6 +1143,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cbc7fdec9d7f6671a3ebb3282c969962aba67c49f6abac5311959b65cafabc10"
 dependencies = [
  "displaydoc",
+ "ryu",
  "smallvec",
  "writeable",
 ]
@@ -2714,6 +2715,7 @@ version = "0.1.0"
 dependencies = [
  "chrono",
  "chrono-tz",
+ "fixed_decimal",
  "fluent-ergonomics",
  "icu",
  "icu_locid",

l10n/Cargo.toml

@@ -8,6 +8,7 @@ edition = "2021"
 [dependencies]
 chrono              = { version = "0.4" }
 chrono-tz           = { version = "0.8" }
+fixed_decimal       = { version = "0.5.5", features = [ "ryu" ] }
 fluent-ergonomics   = { path = "../fluent-ergonomics" }
 icu                 = { version = "1" }
 icu_locid           = { version = "1" }

l10n/src/lib.rs

@@ -1,16 +1,18 @@
 use std::ops::Deref;
 
-use chrono::{Datelike, FixedOffset, NaiveDate, TimeZone, Timelike};
-use chrono_tz::{OffsetName, Tz};
+use chrono::{Datelike, NaiveDate, Timelike};
+use chrono_tz::{Tz};
+use fixed_decimal::{FixedDecimal};
 use icu::{
     datetime::options::length,
-    timezone::{CustomTimeZone, GmtOffset},
+    decimal::{FixedDecimalFormatter},
 };
-use icu_locid::{locale, Locale};
+use icu_locid::{Locale};
 use icu_provider::DataLocale;
-use std::str::FromStr;
 use sys_locale::get_locale;
 
+pub use fixed_decimal::FloatPrecision;
+
 #[derive(Clone, Debug)]
 pub struct L10N {
     locale: Locale,
@@ -137,8 +139,15 @@ impl L10N {
         formatter.format_to_string(&icu_date.to_any()).unwrap()
     }
 
-    fn format_f64(&self, value: f64) -> String {
-        unimplemented!()
+    fn format_f64(&self, value: f64, precision: FloatPrecision) -> String {
+        let fdf = FixedDecimalFormatter::try_new(
+            &self.locale.clone().into(),
+            Default::default()
+            ).expect("locale should be present");
+
+        let number = FixedDecimal::try_from_f64(value, precision).unwrap();
+
+        fdf.format_to_string(&FixedDecimal::try_from_f64(value, precision).unwrap())
     }
 }
 
@@ -259,6 +268,25 @@ mod tests {
 
     #[test]
     fn it_formats_a_number_according_to_locale() {
-        unimplemented!()
+        let mut l10n = ref_l10n();
+
+        assert_eq!(
+            l10n.format_f64(100.4, FloatPrecision::Floating),
+            "100.4",
+            );
+        assert_eq!(
+            l10n.format_f64(15000.4, FloatPrecision::Floating),
+            "15,000.4",
+            );
+
+        l10n.set_locale("de-DE".to_owned());
+        assert_eq!(
+            l10n.format_f64(100.4, FloatPrecision::Floating),
+            "100,4",
+            );
+        assert_eq!(
+            l10n.format_f64(15000.4, FloatPrecision::Floating),
+            "15.000,4",
+            );
     }
 }